# Day 03
```elixir
Mix.install([
{:kino, "~> 0.14"},
{:nimble_parsec, "~> 1.4"}
])
example_input =
Kino.Input.textarea("example input:")
|> Kino.render()
real_input = Kino.Input.textarea("real input:")
```
## Common
<!-- livebook:{"reevaluate_automatically":true} -->
```elixir
defmodule AOC do
def parse(input) do
input
|> Kino.Input.read()
|> Parser.parse()
|> case do
{:ok, acc, "", _, _, _} -> acc
end
end
end
defmodule Parser do
import NimbleParsec
disable =
ignore(string("don't()"))
|> tag(:disable)
enable =
ignore(string("do()"))
|> tag(:enable)
operand = integer(max: 3, min: 1)
mul =
ignore(string("mul("))
|> concat(operand)
|> ignore(string(","))
|> concat(operand)
|> ignore(string(")"))
|> tag(:mul)
instruction = choice([disable, enable, mul])
instructions =
eventually(instruction)
|> repeat()
defparsec(:parse, instructions |> eventually(eos()))
end
```
## Part 1
<!-- livebook:{"reevaluate_automatically":true} -->
```elixir
defmodule Part1 do
def process(instructions) do
instructions
|> Enum.reduce(0, fn
{:mul, [a, b]}, acc -> acc + a * b
_, acc -> acc
end)
end
end
real_input
|> AOC.parse()
|> Part1.process()
```
## Part 2
<!-- livebook:{"reevaluate_automatically":true} -->
```elixir
defmodule Part2 do
def process(instructions) do
{_, sum} =
instructions
|> Enum.reduce({:enabled, 0}, fn
{:mul, [a, b]}, {:enabled, sum} -> {:enabled, sum + a * b}
{:disable, _}, {:enabled, sum} -> {:disabled, sum}
{:enable, _}, {:disabled, sum} -> {:enabled, sum}
_, acc -> acc
end)
sum
end
end
real_input
|> AOC.parse()
|> Part2.process()
```
